Throttle cables

If it's broken or just needs tweaked

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bandwidth69
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Location: North Wales, UK

Throttle cables

Postby bandwidth69 » Sun Aug 20, 2006 10:35 am

Iv mentioned elsewhere in the forum that the throttle cable broke on the old girl today. I say "cable" as there's only the one. In fact, i think this one is so badly butchered that it has to be the "close" cable and not the "open" cable. (swapping them over if one breaks is a common fix is it not?) I'm not sure coz this is something that I inherited when i got the bike and until now the "if it aint broke don't fix it" mentality had applied. well...now its broke!

My question is this. Got a PAIR of Nighthawk cables of roughly the same 79 vintage as my Z. Will these fit? The bikes outside, but the cables are at a friends house waiting to be picked up (doh!) . Will they be a direct replacement does anyone know? Thanks in advance.

Oh, you know when stupid questions pop into your head at 3am? That happened to me last night. Ponder this one if you dare.

My CB runs these K&N filter things. They weigh nothing at all, but it got me thinking. If you run the standard set-up (carbs and full airbox) the carbs are supported by the airbox, which is attached to the rear mudguard. This helps keep things nice and straight and tight. If you, like me, take the airbox away, then the carbs have no support and depend on the rubber manifolds for anchorage and stability. Mine, though not drastically, tilt downwards a few degrees towards the engine block. They droop just a teensy weensy bit. (thats technical talk that is)
Guys, Is it worth trying to support the carbs a bit more? maybe to give the carbs morre stability? Is this downward tilt crucial to the way the bike will run and perform? If hung "straight" maybe things will run more smoothly?

I dunno. Someone tell me to shut up! :shock:
i dont watch big brother

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DammitDan
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Postby DammitDan » Sun Aug 20, 2006 1:03 pm

I would recommend supporting the carbs, as any pressure put on those rubber manifold boots increases you chances of an air leak.

Why not just tie them on with wire and loop it over the center frame brace or fashion a bracket of some sorts? It will probably save you a headache in the future.

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bandwidth69
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Location: North Wales, UK

Throttle cables

Postby bandwidth69 » Sun Aug 20, 2006 1:10 pm

Thanks. i'm not mad am I? I was sure there was a valid reason for looking at the issue of "drooping" carbs more closely. Yes, of course you are right. Come to think of it, the rubber boots i have are a replacement to the originals that were, on inspection, completely useless. OK then. Worth tying the carbs up to the frame.

Got a friend with a kawasaki GPZ 305 whose desperate to go out for a spin. Going to try a Kwak throttle cable on the old girl, just to see what happens.

Thanks for your help! :D
i dont watch big brother

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bandwidth69
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Joined: Fri Aug 18, 2006 3:53 pm
Location: North Wales, UK

Throttle cables

Postby bandwidth69 » Sun Aug 20, 2006 3:57 pm

Kwak items didn't work. too short. We used an inner cable from a pushbike, with a nylon washer as an added flange arrangment. offered it up to the throttle grip, then fed it through the frame, back onto the carbs. Cut to length. Attached the "universal nipple" (im sure there's a proper word for it. A stopper with a hole for the cable and a grub screw to tighten it up!) and she fired and went no problem. Also, tied the carbs up with the broken cable as an added measure. Used the rubber handle of a hammer as a lever, pushed the carbs up a few mill while my friend got busy with the knots at the top. Not preety, but it'll be interesting to note if there's a change in the running of the bike now. Took her out for a spin. Going great. Though Iv noticed my numberplate and clock dials aren't illuminating as they should. Always something eh?

Thanks everyone. :)
i dont watch big brother

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Chris
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Postby Chris » Sun Aug 20, 2006 9:42 pm

Hehe, no bailing wire or duct tape? You sound like a pretty thrifty guy. That's very admirable, but I'd be careful... safety first :)
1980 CB650c

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Volker_P
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Re: Throttle cables

Postby Volker_P » Mon Aug 21, 2006 1:18 am

The main support for carbs with stock airbox is also given from the carb rubber boots. The airbox side rubbers are not stiff enough for any mechanical support, at most they might avoid some oscillations. But oscillations is exactly the point for which an additional support may make sense in your case. However it should not be too rigid (include some rubber somewhere), as undamped engine/frame vibrations may increase wear of carb moving parts.


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